This invention relates to a fluid heat exchanger, and in particular to a flat, very thin heat exchanger of up to no more than about one eighth inch in thickness. This invention also relates to an improved method for fabricating and assembling a thin, flat heat exchanger which insures its accurate and leaktight characteristics.
It is well known that cooling is necessary to avoid damage to many thermoelectric devices. Fans and various types of heat exchangers are used to effect cooling. There remains, however, a need for improved cooling media, and particularly for use in environments where space is limited and the configuration of the device to be cooled limits the type and nature of heat exchangers which may be used. Micro and mini computers are typical of difficult to cool environments, particularly for some zones of the computers. The thin, flat, compact and efficient heat exchanger of the present invention is adapted for uses in existing environments which are not conveniently or readily coolable in an expedient fashion currently.
A variety of heat exchanges and methods for producing such exist in the art including processes which have employed etching techniques to produce them. For example, Little U.S. Pat. No. 4,392,362 discloses a miniature refrigerator in which micron-sized fluid passages are defined in internal surfaces of a laminate by techniques such as etching. Solar collector panels have been formed by etching a pattern of grooves as shown by Benjamin U.S. Pat. No. 4,331,503. Generally flat heat exchangers are shown in Berkowitz et al. U.S. Pat. No. 3,800,868 and a generally flat solar panel having internal passages with peripheral seals is shown in Severenson U.S. Pat. No. 4,161,809. Hopkinson et al. U.S. Pat. No. 3,334,401 shows the etching of channels of desired shape for fluid logic and like systems.
Sanz U.S. Pat. No. 2,739,047 discloses chemically milled structural shapes, such as rocket booster casings and structural panels and the like. Sanz discloses that etched out areas may be desirable for a variety of purposes including forming elongated passages for the conduction of coolant fluid.
However none of the prior art patents discloses a thin flat heat exchanger, as of no more than about one-eighth inch in thickness, in which flat elements defining a passageway are brazed together and which define openings, including an opening for an element of an object to be cooled, nor do the patents disclose a process in accordance with the present invention.